Typewriting machine



c.. w. CRUMRINE TYPEWRITNG" MACHINE Sept. I3, 1938.

Original Filed Sept. 18, 1935 ATTORNEY Patented sept. 13,1938 v2,129,650

UNITED STATES PATENT oFEicE 2,129,650 TYPEWRITING MACHINE Chester W. Crumrlne, Rochester, N. Y., assignor to International Business Machines Corporation, New York, N. Y., a corporation of New York originel application september 1s, 1935, serien No. 41,021. Divided and this application November 18, 1935, Serial No. 50,103

8 Claims. (Cl. IS7-64) This invention relates to improvements in govother. When adjusted to reduce or prevent ernors or brakes used in typewrlting machines shocks at the beginning of a line they are apt and other machines having carriages. to make the carriage move too slowly at the end The present application is a division of coof a line. On the whole, present forms of govpending application Serial No. 41,021 iiled Sepernors for typewriter and like carriages are still tember 18, 1935, by Chester W. Clrumrine. far from being completely satisfactory.

The primary object of the present invention is The present invention provides an automatic to provide an improved carriage brake or govcounterbalancing or tension equalizing governor ernor in which the braking or retarding force is which compensates for the variation in tension l0 automatically varied according to the displaceof the carriage power-spring so that tabulating ment of the carriage. and other movements of the carriage may be ef- Other objects, advantages, and features of the fected smoothly and with little shock regardless invention will be particularly pointed out in `the of the length of such movements or whether they following description and claims or will be oboccur near the beginning 01 end 0f a line. This vious from a study of the description, claims, governor is built into the usual power-spring unit and drawing. generally designated with the reference numeral In the drawing: 45 in the drawing. Fig. 1 is a large scale rear elevation showing Rotatably mounted on a screw stud 85 carthe governor attached to the machine. ried by a xed part of the framework is a hub Fig. 2 is a horizontal section on the line 2-2 in 86 to which is secured a anged disc 81. A ring Fig. 1. 88 ls welded or brazed to disc 81 and co-oper- Purely as a matter of convenience, the present ates with an axial flange and a 10W radial flange invention will be described in connection with formed in disc 81 to provide a ShallOW guide-Way the well-known Electromatic typewriter and or channel for a tape 89 which iS removably 5 accordingly has been shown ln this machine. attached to the disc 81 and also to the carriage 20. It is desired to point out, however, that the pres- A brake disc in the form of a ratchet wheel 90 is ent invention may be used with other typewritloosely mounted on hub 86 adjacent disc 81 and a ing machines, whether power-driven or manuring 9| of suitable vfriction material, such as comally operated, and may also be used in statistical position brake lining or clutch facing, is interrecord card punching machines, or other maposed between'the ratchet wheel 90 and disc 81, chines wherein carriages are used. the ring 88 holding the ring 9| concentric with In the ordinary typewriter, the tension of the hub 86. The hub 88 is provided With SCreW power-spring which causes the letter spacing and threads 92 on which a nut 93 is threaded. tabulating movements varies considerably be- Interposed between nut 93 and ratchet wheel 90 tween the limits of the carriage travel. The is a multi-prong spring member 94 having four power-spring must have sufficient tension to move Spring DI'OngS which tend i0 DIGSS the ratchet the carriage rapidly near the end of the line but wheel 90 and ring 9i toward disc 81. Nut 93 is when its tension is adjusted to produce this held against rotation by a slot in a plate 95 result the spring will have too much tension for Secured t0 a Xed part of the machine frame.

40 moving the carriage at the beginning of a line. The entire assembly comprising the parts 86 This variation in tension of the power-spring has to 84, with the exception of nut 93, is rotatable little harmful eiect on the escapement mechaon stud 85. 1t is plain that rotation of this nism but has a harmful effect on the parts of assembly Causes nut 93 t0 travel alOng hub 86 the tabulating mechanism, such as the. tabular and thereby vary the tenSOn 0f Spring 94. This stop, column stops, and parts which support these has the effect of varying the frictional force which stops. The excessive tension of the power-spring must be exerted in order to rotate disc 81 rela- `at the beginning of a line causes the carriage to tive to the ratchetwheel 90. The parts are so move too fast with the result that some of the designed that the tension of spring 94 and hence column stops strike the tabular stop lever with a the braking force between disc 81 and ratchet considerable shock. wheel 90, increases as the carriage moves toward Attempts to avoid this shock during tabulating the position determined by left-handA marginal operations usually take the form of dash-pots or stop 11 and decreases with movement in the opcentriugal governors which are only partially posite direction, successful since they have a fixed setting which Rotatably mounted on stud 85 is a worm wheel does not vary from one end of the line to the 96 having a recessed portion 96a which iits over a collar 91 loose on hub 88. The recessed portion 86a is slightly loose on hub 88. The recessed portion 86a is slightly flattened to fit in oblong holes in a spring hook 88 and a pair of spacing washers 98 which hold the hook in the center of the recessed portion 98a. A large disc |00 is also provided with an oblong hole to t the recessed portion 96a, and the worm wheel 88, spring hook 88, washers 88, and disc |00 are all secured together as a unit by staking or otherwise securing the left-hand washer 88 (Fig. 2) to the recessed portion 86a. This assembly is rotatable on stud 85. The power spring |0| is anchored at its inner end to spring hook 88 while its outer end is' secured to the inside of the axial ange of disk 8 The frame carrying the stud has a ilange |02 enclosing the worm wheel 88. The flange is nearly circular but is shaped to form a pocket |02a the walls of which have a pair of slots or notches. Housed in this pocket and journaled loosely in the notches, is a worm |08 meshing with Worm whe-el 96. The worm may'have a slotted head (not shown) whereby it may be turned with a screw driver or other instrument to regulate the tension of the power spring.

Normally the ratchet wheel 80 is free to rotate with disc 81 and there is no braking effect on the latter although nut 88 oscillates back and forth on hub 86 during line writing and carriage return operations of the carriage. 'Ihe tabulating mechanism is adapted to control the governor through means shown in Fig. 1.

A three-armed lever |04 is pivotally mounted on a stud |05 carried by the framework. One arm of lever |04 is connected by a link |06 to one arm of a bell crank |01 pivoted on a stud |08 carried by a bracket |09. As explained in Patent No. 1,935,436, bracket |09 also provides a mounting for the arm 40. The other arm of bell crank |01 has a rectangular slot or notch loosely embracing the lever 33 adjacent arm 40.

One arm of lever |04 extends downwardly close to ratchet disc 80 and has a pin |04a loosely tting in an L-shaped slot in one end of a pawl ||0. The other end of pawl ||0 is slotted to embrace a shoulder in stud |05. A spring connects pawl ||0 to the third arm of lever |04 and tends to hold pawl in the position shown in Fig. 2 with pin |04a in the apex of the L-shaped slot. Pawl ||0 has a bent-over lug |0a adapted to engage the teeth in ratchet wheel 90.

The operation of the above parts will now be explained in detail.'

When the usual tabulating key is depressed, a cam unit associated therewith operates lever 83 as described in the above patent, through a link 39 and an arm 40, causing the left-hand end of lever 33 in Fig. 1 to move forwardly. This causes bell-crank |01 to be rocked in a direction to push link |06 downwardly. As a result lever |04 is rocked clockwise in Fig. 1 carrying lug ||0a into engagement with the teeth of ratchet wheel 80.

The carriage now starts to move to the right in Fig. 1 under the force of power spring |0|, the escapement pawls 42 having been released in the usual way, with the result that ratchet wheel 80 will rotate clockwise and pawl ||0 will be drawn longitudinally downward against the tension of spring Eventually the pin |04a and stud |05 will prevent further longitudinal movement of pawl ||0. At this point the ratchet wheel 80 will 'be held positively against further clockwise movement but spring |0| will continue to rotate the disc 81 and move the carriage until one oi' the column stops strikes the lug 33a in tabular lever 88.

The amount of braking eil'ect between the ratchet wheel 80 and disc 81, and hence the speed of the carriage, will depend on the position of nut 88 on hub 86. If the carriage movement commences near the beginning .of a line, that is, when the carriage is at its extreme righthand position (which is the extreme left-hand position in Fig. 1). the tension of spring |0| will be a maximum while nut 93 making the braking force a maximum.

At the other limit of carriage travel, both the tension of spring |0| and the braking force will be a minimum because the nut 93 will then j occupy the position farthest from disc 81.

It may happen that the depression of the tabulating key occurs at a time when one of the teeth in ratchet 80 is almost directly opposite the lug ||0a. This is possible because the teeth in ratchet 80 do not have the same spacing as the teeth in rack 44 and therefore may at times prevent full movement of pawl ||0. If the lug ||0a were integral with lever |04, the obstruction of its movement by ratchet wheel 90 would have'the eilect of wholly or partly blocking movement of lever 88 and arm .40, thereby jamming the cam unit which operates arm 40 against the power roller and preventing proper operation of the tabulating mechanism. The L-shaped slot in pawl ||0 permits the lever 04 to move the required amount regardless of any obstruction offered by the teeth of ratchet wheel 80.

The slotted mounting of pawl ||0 also allows the carriage to move a few letter spaces before any braking action takes place. The ratchet wheel 90 has approximately half as many teeth as the escapement rack 44, whereas the latter has half as many teeth as there are letter spaces of movement. It follows, therefore, that approximately four letter spaces of movement of the carriage take place for each tooth space on`ratchet wheel. The slots in pawl I0 are such length that approximately ve letter spaces of movement of the carriage take place before ratchet wheel 90 is positively arrested. During this movement the only retarding force offered to movement of the carriage is the negligible force exerted by spring The above feature of the governor mechanism enables short tabulating movements to be effected without the sluggishness of response often experienced with common forms of carriage governors.

A feature of the governor is that it is not limited to use in connection with tabuiating mechanism but may be used generally as a means for equalizing the tension of the power spring for the purpose of obtaining a more uniform tension throughout the travel of the carriage. This may be done by fixing the ratchet wheel 90 against rotation or simply by using a fixed disc not provided with teeth. This would have the effect of automatically compensating for variation in the tension of the power spring by subjecting the carriage at all times to a braking force which varies according to the tension of the power spring. This feature would be particularly useful on machines equipped with very wide carriages. On carriages of extreme width, such as the twenty-inch carriages often used on machines for accounting and statistical work, for example, the variation in tension of the power spring is quite great with the result that letter spacing and A l:1,129,659 Y I tabulating movements are apt to be sluggish near the end of aline of writing.

- adapt the invention to requirements of service,

yis apparent that without departing from .such principles.. It" is desired, therefore, that the following claims be limited only by the state of the prior art.' What is claimed is:

1,. A carriage governor comprising a'dsc ro-v tatable in'proportion to movement oi' the care,lv riage, a brake disc co-operating with the firstnamed disc, spring meansurging the brake disc v increaseand decrease nisrn f^r preventing intobraking relation with the rst-named disc,

a-'traveling member operable in two' directions to the tension ofthe spring means, andl means operated by the first discfor moving the traveling member in one direction 'or 4anotherl according to the direction oi?` movement j of the carriage and in proportion to carriage` movement. s

2. A carriage governor comprising a'4member rotated in proportion'to movement f the car` riage including a threaded said member, a brake member co-acting with the rotatable member and loosely mounted .ony the hub, a nut carried by the hub, means for pre-- `venting rotational movement of the nut while permitting it to move axially of the hub',v and-a brake spring on said hub betweenA said vnut and said brake member, said nut being ,operative to increase or decrease the tension of the spring automatically according to the direction of rotation of the rotatable member.

3. In combination with a carriage, a brake comprising f two coacting elements both moved when' the carriage moves', tabulating mechanism, means connected with Vthe tabulating mechamovement of one of said elements upon an operation of the tabulating mechanism whereby to render thel brake eiective, and means m'ovable in proportion to movement ofthe carriage for varying the braking effect of` one brakeelement on the other.

4. In combination with a carriage, a pair of L brake discs movable with the carriage, tabulating mechanism, means operative during an operation of the tabulating mechanism 4purpose of illustrating l which its operation depends, it`

brake comprising two -effective,'and means l I .z urging 'means'is regulated in proportion to carriage movement.A j

to engage Vwhereby both discs normally rotate .in proporhub rotatable withto movement of the to prevent movement of one of thev brake discs whereby to render the brake effective, and means moved in proportion to movement of the carriage lfor varying the brake'pressurebetween said discs. 5. In combination with a carriage, a carriage .coacting rotatable brake discs. .means connected to thecarriage for rotating oneofsaid discs, spring means to urge the other disc into engagement 'with the carriage moved'disc whereby .both discs normally rotate in proportion to movement of the carriage, means to arrest the second, disc .to' render the brake `whereby the effect of the 6. In combinatio` ywith a' carriage, a pair of brake discs, means to rotate one of said discs in proportion .to movement of thel carriage, means the second. disc with the iirst disc tion to carriage movement, means movable in proportion to'carriage movement for varying the effect ofthe engaging means,4 and means to arv rest the movement of the second disc to render the brake effective. 4-

'7. In.- combination with acarriage, a brake disc havingafconnection to the carriage so as to berotated in proportion to carriage movement,l

a second disc co-axial-with the first disc, spring `means for engaging one of `thediscs with thel other, a traveling member movable in two directions to` increase and spring means, and connections between the carriage and the traveling member for operating the latter according to the direction of carriage movement.

8; In combination with a carriage, a carriage brake including a. pair of brake members each lmovably mounted independently of the carriageh means to move one of said members in proportion to movement of the carriage, means ,to engage the second brake member with the iirst member whereby both brake members normally move` with the carriage, means movable in proportion carriage for controlling the engaging means to vary the engaging pressure between the brake members in accordance with the position of the carriage, and means to prevent movement of the second brake member to thereby render the brake eiiective.

CHESTER W. CRUMRIN'E.

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decrease the 'tension of the 

